“The repeated form of dealing with relations, especially in the field of energy, between Russia and other countries should raise concern for the whole of Europe,” Grybauskaite told reporters.

Russia on Wednesday cut gas supplies to Belarus by 60 percent, as a payment feud between the ex-Soviet neighbours that has raised fears for European consumers went into a third day.

The dispute is a particular worry for Lithuania, since the Baltic state relies entirely on Russia for gas supplies piped via Belarus.

Grybauskaite said that Lithuania so far remained unaffected but was preparing to import supplies from neighbouring Latvia if necessary.

“The gas flow to Lithuania has not been reduced. Lithuania has the possibility of using reserves in Latvia in the event of a critical situation. We believe bilateral issues between the two countries should be resolved,” she said.

The EU closely watches gas disputes between Russia and its ex-Soviet neighbours after a row between Moscow and Kiev led to supplies of Russian gas to Europe via Ukraine being cut off for two weeks early last year.

That dispute remains firmly etched in the minds of European policymakers as it left several EU countries deprived of gas during a harsh winter.

“That is why we are saying that the security of supply of gas and other energy sources should be guaranteed, particularly for EU countries. This is a common matter,” Grybauskaite said.

Former communist countries such as Lithuania which count on Russian gas have repeatedly pushed for the 27-nation EU to develop a joint energy policy.